scholarly journals Geomorphology, Mineralogy, and Geochronology of Mare Basalts and Non-Mare Materials around the Lunar Crisium Basin

2021 ◽  
Vol 13 (23) ◽  
pp. 4828
Author(s):  
Xuejin Lu ◽  
Haijun Cao ◽  
Zongcheng Ling ◽  
Xiaohui Fu ◽  
Le Qiao ◽  
...  

The Nectarian-aged Crisium basin exhibits an extremely thin crust and complicated lunar geological history. This large multi-ring impact basin is characterized by prolonged lunar volcanism ranging from the Imbrian age to the Eratosthenian period, forming the high-Ti mare unit, low-Ti mare basalts, and very low-Ti mare unit. We produced an updated geological map of the Crisium basin and defined four mare units (Im1: 3.74 Ga; Im2: 3.49 Ga; Im3: 3.56 Ga; EIm: 2.49 Ga) in terms of distinct composition and mineralogy. Olivine was widely determined in the Ti-rich Im1, implying the hybridization source in the lunar mantle with the occurrence of small-scale convective overturn. The major phase of low-Ti basaltic volcanism occurred c.a. 3.5 Ga, forming Im2 and Im3 in the western area. The youngest mare unit (EIm) has slight variations of pyroxene compositions, implying a decrease of calcic content of basaltic volcanisms with time. Later, distal material transports from large impact events in highlands could complicate the mixing of local mare basalts in the Copernicus age, especially the Im3 unit. The identified olivine-bearing outcrops and widely Mg-rich materials (Mg# > 70, where Mg# = molar 100 × Mg/(Mg + Fe)) in the western highlands, assumed to be the occurrence of the Mg-suite candidates, require future lunar exploration missions to validate.

1986 ◽  
Vol 286 (5) ◽  
pp. 361-389 ◽  
Author(s):  
J. F. Kasting ◽  
S. M. Richardson ◽  
J. B. Pollack ◽  
O. B. Toon

2010 ◽  
Vol 106 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Joanna Alfaro-Shigueto ◽  
Jeffrey C. Mangel ◽  
Mariela Pajuelo ◽  
Peter H. Dutton ◽  
Jeffrey A. Seminoff ◽  
...  

2020 ◽  
Author(s):  
Kristine Asch ◽  
Andrea Naß ◽  
Stephan van Gasselt

<p>The project of the International Quaternary Map of Europe project (IQUAME 2500) is a major international initiative coordinated by BGR under the auspices of the CGMW (Commission of the Geological Map of the Word, Sub-Commission Europe) and with support of INQUA (International Union for Quaternary Research). It started in 2011 at the INQUA congress in Bern and aims to show the distribution of Quaternary features at the land surface and general marine deposits across the entire European continent. The map is planned as web-based geographical information system (GIS) and is going to include the Quaternary on- and off-shore information on e.g. glaciogenic elements, geomorphologic features, age and lithology of Quaternary units, last extent of ice sheets (Weichselian, Saalian, if possible Elsterian), faults, active faults off-shore Quaternary information (in cooperation with the European Union EMODnet Geology project) and more.</p><p>Partner institutions from more than 30 countries including geological survey organisations from Russia in the East, Portugal in the West, Norway in the North and Cyprus in the South are participating; a scientific board of Quaternary researchers ensures the high scientific quality of resulting map. For a multinational and cross-boundary project like this, international collaboration is the key to success. This project requires that data originally set up in a plethora of regional and national classifications need to be adapted, integrated and harmonized in respect to semantics, structure and geometry. To achieve this aim common rules needed to used such as those defined by the European INSPIRE Directive or be set up and applied by all participants:  structured vocabularies (incl. definitions of terms) to describe the above contents, cartographic guidelines to suite the scale and last but not least generally applicable tools to aid the partners to submit their data to the project.</p><p>Ultimately, the aim is to create an pan-European, internationally harmonized, comprehensive, spatial geological database where relevant properties of the Quaternary layers can be retrieved, combined, selected and cross-referenced across political boundaries and also to provide a summary of the current status of European Quaternary geological research.</p><p>Looking at planetary mapping, e.g. of Mars and Moon, there are several similarities. The surfaces of terrestrial planets are shaped by geologic processes that are similar to those operating on Earth, therefore endogenic and exogenic landforms (such as lava flows, glacial deposits, and impact craters) are regularly mapped by the scientific community.  Beside specific scientific mapping projects conducted by individual researchers and groups different organisations and institutes are producing planetary maps, such as NASA, ESA, ROSCOSMOS and MIIGAiK (Russia), USGS (USA), CAS/NOAC/SGCAS/RADI (China), DLR (Germany), or the British Ordnance Survey. This presentation aims to introduce the small-scale Quaternary mapping of one part of planet Earth, i.e. Europe, to present its collaborative aspects, to highlight the parallels to planetary mapping and to suggest potentially useful aspects for planetary geological mapping projects.</p>


2019 ◽  
Author(s):  
Christian Barthlott ◽  
Andrew I. Barrett

Abstract. The mesoscale convective system (MCS) that affected Germany at Pentecost 2014 (9 June 2014) was one of the most severe for decades. However, the predictability of this system was very low as the operational deterministic and ensemble prediction systems failed to predict the event with sufficiently long lead times. We present hindcasts of the event using the COnsortium for Small-scale MOdeling (COSMO) model at convection-permitting (2.8 km) resolution on a large (1668 × 1807 km) grid, which allowed us to simulate the whole life cycle of the system originating from the French Atlantic coast. Results show that this model configuration successfully reproduces the convective events of that day. However, the low predictability of the event was evident by the surprisingly large impact of tiny changes to the model domain. We systematically shifted the model domain by one grid point in eight different directions, from which three did not simulate any convection over Germany. The analyses show that no important differences in domain-averaged initial conditions nor in the preconvective environment ahead of the convective system exist. That one-third of these seemingly identical initial conditions fails to produce any convection over Germany is intriguing. The main reason for the different model results seems to be the proximity of the track of the initial convective system to the coast and colder sea surface. The COSMO model simulates small horizontal displacements of the precursors of the MCS which then determine if the cells dissipate close to the sea or reach a favourable area for convective development over land and further evolve into an MCS. This study demonstrates the potentially huge impact of tiny model domain shifts on forecasting convective processes in this case, which suggests that the inclusion of this simple method in convective-scale ensemble forecasting systems should be evaluated for different cases, models and weather regimes.


2021 ◽  
Author(s):  
Caroline Eakin

Abstract Australia is an old stable continent with a rich geological history. Limitations in sub-surface imaging below the Moho, however, mean that is unclear to what extent, and to what depth, this rich geological history is expressed in the mantle. Scattering of surface waves at ~150km depth by lateral gradients or boundaries in seismic anisotropy, termed Quasi-Love waves, offer potential new insights. The first such analysis for Australia and Zealandia shown here detects over 300 new scatterers that display striking geographical patterns. Around two-thirds of the scatterers are coincident with either the continental margins, or major crustal boundaries within Australia, suggesting deep mantle roots to such features. Within the continental interior such lateral anisotropic gradients imply pervasive fossilized lithospheric anisotropy, on a scale that mirrors the crustal geology at the surface, and a strong lithosphere that preserves this signal over billions of years. Along the continental margins, lateral anisotropic gradients may indicate either the edge of the thick continental lithosphere, or small-scale dynamic processes in the asthenosphere, such as edge-drive convection, tied to the transition from oceanic to continental crust/lithosphere.


Author(s):  
Nikhil Potu Surya Prakash ◽  
Kenn Oldham

A finite element dynamic model is developed to better understand impact events during large amplitude dynamics of a compliant, elastic-legged small-scale robot. The proposed motion of the robot would be achieved as a result of impulse forces generated from the forced collision of piezoelectrically-actuated, beam-like legs with the ground. The nominal robot leg is a prismatic continuous structure with uniform density, cross-sectional area and moment of inertia. Dynamic modeling in this work attempts to manage the non-negligible motion of the actuated beam tip in its axial direction at impact when large bending deformations are excited, which complicates prior analysis methods. For the micro-robot, this motion is proposed to be exploited as a means to produce locomotion in the horizontal direction, and hence must be accounted for. Finite element analysis approaches are adapted for the micro-robotic circumstances. Preliminary results are presented for the scenario of large deformation, unforced dynamics with impact, tested using centimeter-scale mock-ups for future thin-film based micro-robots. Needs and opportunities for further validation are briefly discussed.


Author(s):  
V. S. Kulikov ◽  
V. V. Kulikova ◽  
A. K. Polin

A new chronostratic scheme of South-East (SE) Fennoscandia has been developed, based on the International Stratigraphie Scale, taking into account some elements of the Common Stratigraphic Scale of Russia and the regional stratigraphic scheme of the North-West (NW) of Russian Federation. A rank of Archean and Proterozoic stratons has been determined (including supersystems for Riphean and Archean geonotems), compatable in dutation to the Phanerozoic systems (Mesozoic and Paleozoic ones). An original coloring for the geological maps of the newly allocated systems and their analogues in the Precambrian, as well as the digital indexing of all stratons of the rank of systems instead of the traditional alphabetic one, have been proposed. Based on the extensive geological materials of the Institute of Geology of Karelian Research Centre of the Russian Academy of Sciences, in view of the new approaches and reliable geochronological data, an areal geological map of SE Fennoscandia in scale 1: 750 000 has been created, which includes the territory of Karelia and adjacent areas of the Russian Federation and eastern Finland. The proposed chronostratic scheme can serve as a basis for developing legends of small-scale state geological maps of the new generation, especially in the regions of the Precambrian development.


2019 ◽  
Vol 45 (1) ◽  
pp. 143 ◽  
Author(s):  
D. González-Álvarez

Current debates around the Anthropocene tend to focus on recent planetary-scale processes. However, regional and small-scale processes can be very telling about human agency in the shaping of landscapes overtime. Indeed, anthropogenic impacts of different intensities can be observed on landscapes since Prehistory – even in such remote and allegedly marginal areas as deserts, wetlands or mountains. In this article, I reflect on the long-term anthropization of alpine and subalpine areas in the western area of the Cantabrian Mountains (North-West of Iberia) in Later Prehistory. Studying the earlier anthropogenic pressure on upland environs in this period reminds us of the potential of landscape archaeology to enhance interdisciplinarity in debates about the Anthropocene. With the aim of emphasizing the role of archaeology as a mediating arena between social sciences, humanities and earth sciences, I analyse the scarce archaeological information available for upland landscapes of this study area to show how these datasets can nuance evolutionary interpretations of paleo-environmental sequences studied at natural deposits. Only through integrated and comprehensive discussions around the cultural and environmental traits of landscapes will we be able to fully understand the complex social contexts where agrarian labour and collective action shaped the alpine and subalpine areas in the Cantabrian Mountains since the spread of the Neolithic.


Author(s):  
C. A. Lorenz ◽  
E. V. Korochantseva ◽  
M. A. Ivanova ◽  
J. Hopp ◽  
I. A. Franchi ◽  
...  

2021 ◽  
Vol 40 (2) ◽  
pp. 503-537
Author(s):  
EDWARD P. F. ROSE

Malta, an island in the central Mediterranean Sea, was fortified as a base for the Knights Hospitaller 1530–1798 and to provide major harbours for the British Royal Navy after 1813. Men with British military associations (all subsequently to attain some distinction in public and/or academic life) were amongst the many pioneers of Maltese geology who established the essence of its outcrop stratigraphy and structure: a circa 300-metre-thick sequence of near-horizontal mid-Cenozoic fossiliferous limestones punctuated by a ‘blue clay/marl’, cut by a series of major faults and penetrated by several caves and fissures whose infill contained significant remains of Pleistocene vertebrates. Between 1843 and 1856, Lieutenant (later Vice-Admiral) Thomas Abel Brimage Spratt (1811–1888) defined major units in the bedrock sequence, Colonel (later Major-General) Sir William Reid (1791–1858) promoted publication of a geological memoir, and a 1:31,680-scale geological map prepared by the 3rd Earl of Ducie on a Royal Engineers topographical base map was published under Royal Engineer auspices. Mostly between 1860 and 1866, Captain (later Professor) Frederick Wollaston Hutton (1836–1905) and Surgeon (later Deputy Surgeon-General and Professor) Andrew Leith Adams (1827–1882) made field observations that refined earlier interpretations of stratigraphy and structure and generated revised but small-scale maps. They also collected specimens that facilitated specialist identifications of Malta’s fossil faunas, including foraminifera by Thomas Rupert Jones (1819–1911), Professor of Geology at the Royal Military College, Sandhurst. Rock specimens were sent in 1888 by Surgeon-Captain David (later Surgeon-General Sir David) Bruce (1855–1931) and the former engineer Lieutenant (and later Professor) Osbert Chadwick (1844–1913) to the pioneer oceanographer John (later Sir John) Murray (1841–1914). They stimulated Murray’s benchmark study 1889–1890 of Malta’s sedimentary sequence and fossil foraminifera, and their palaeoenvironmental interpretation, plus his compilation of a 1:129,254-scale geological map. These prompted extensive local studies and collection of macrofossil specimens by schoolmaster (later Lieutenant-Colonel) John Henry Cooke (1862–1933). By the end of the century, representative Maltese fossils had been presented for specialist study and identification or description to major museums in England, Scotland and Italy, facilitating improved correlation of Maltese strata with Oligo-Miocene successions elsewhere.


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